The present invention relates to a method and device for identifying a half point of a pedal on a keyboard musical instrument, and a non-transitory, computer-readable storage medium storing therein a program for identifying such a half point. The present invention also relates to a method and device for reproducing a half point performance of a pedal on a keyboard musical instrument, and a non-transitory, computer-readable storage medium storing therein a program for reproducing such a half point performance.
Heretofore, keyboard musical instruments have been known which can generate sounds by striking strings (string sets) via hammers as in an acoustic piano and which include depressable pedals. Among such pedals is one which is designed to make variable non-key-depressed-state corresponding positions (i.e., rest positions) that are initial relative positions of hammers relative to string sets in a non-key-depressed state. Such a pedal is commonly called “shift pedal” in the grand piano or “soft pedal” in the upright pedal.
In the case of the grand piano, a key frame moves horizontally in a left-right direction relative to string sets, so that non-key-depressed-state corresponding positions (rest positions) of hammers too horizontally move in the left-right direction. In the grand piano, the number of component wire members (i.e., string elements) constituting the string set of each note differs depending on the pitch range which the string set belongs to that is, whereas the number is only one in a lowest pitch range, two wire members are placed in substantially parallel relation to each other in a low pitch range, and three wire members are placed in parallel in medium and higher pitch ranges. If positions at which the string sets are to be struck by the hammers (i.e., hammers' string-striking positions) are shifted in response to depression of the shift pedal, the number of wire members to be struck by each of the hammers changes in the pitch ranges other than the lowest pitch range. Also, in all of the pitch ranges, portions of the hammers actually contacting or abutting against the string sets are shifted in position horizontally.
Further, in the high pitch range, for example, whereas the number of wire members to be struck is “three” when the shift pedal is in a non-depressed state, the number of wire members to be struck is “two” when the shift pedal is in a completely depressed state. Further, in the low pitch range, whereas the number of wire members to be struck is “two” when the shift pedal is in the non-depressed state, the number of wire members to be struck is “one” when the shift pedal is in the completely depressed state. Such arrangements permit variations in sound color and volume.
Also known in the art is a performance expression effected by a human player depressing keys while depressing the shift pedal to a halfway point of a so-called pedal stroke from the non-depressed state or position to a completely-depressed state or position.
Further, a portion of a hammer felt which frequently strikes a string set tends to have a greater dent and greater hardness than the other portions. Thus, if the hammer strikes the string set with a horizontal positional shift relative to the string set, it would strike the string set by its portion differing in dent size and hardness from the frequently-striking portion, thereby resulting in variations in sound color and volume. Therefore, when a key is depressed with the shift pedal depressed to a halfway point, the portion of the hammer striking the string set varies to thereby achieve variations of tone characteristics. Further, in that case, a state where a single wire member located at an end of the string set is struck incompletely can also be realized. In this way, desired subtle variations in sound color and volume can be expressed by a depressing state of the shift pedal.
In the depressing stroke, from the non-depressed position to the completely-depressed position, of the shift pedal, there is a region or point where tone characteristics produced by string striking change. Such a region or point will hereinafter be referred to as a “half region” or “half point” of the shift pedal.
Furthermore, among the conventionally-known keyboard musical instruments is one which can execute an automatic performance, including loud pedal (damper pedal) operations, by supplying a driving electric current to a solenoid coil to thereby drive the loud pedal. In an automatic performance, it is desirable that appropriate pedal operation control corresponding to a half pedal region of the loud pedal be performed in order to enhance reproducibility of the performance. With the shift pedal too, reproducibility of a performance in an automatic performance can be enhanced if appropriate reproduction of the half region or half point can be realized.
However, static and dynamic characteristics of the pedals are characteristics unique to each keyboard musical instrument and differ from one keyboard musical instrument to another depending also on mounted states and conditions of the pedals. Thus, it is difficult to accurately identify a half point in the half region.
Methods for identifying a half point of the loud pedal on the basis of load information of the pedal are disclosed in Japanese Patent Nos. 2606616 and 4524798. However, unlike with the loud pedal to which a damper lifting load starts to be applied even in the middle of a pedal depression operation, it is difficult to identify a half point of the shift pedal on the basis of a load on the shift pedal. Therefore, in a case where tone characteristics of the grand piano are to be controlled, it was impossible to control tone characteristics by use of a half point of the shift pedal. For this reason, it has been desirable to establish a method for accurately identifying a half point of the shift pedal.
Generally, in the case of the upright piano, on the other hand, a distance, to the string set, of the hammer in the non-key-depressed-state corresponding position (rest position) changes in response to depression of the soft pedal. Thus, even when the key is depressed at a same velocity, changing the depressing state of the soft pedal can vary a string striking velocity and hence sound volume. With the uptight-type piano too, it is conceivable to employ a construction where there exists a point at which tone characteristics change. In such a case too, it is desirable to establish a method for accurately identifying a half point of the soft pedal.